i am trying to read the ADC value from the board but the value seems to fluctuate quite a lot.
I tried using the multimeter to probe the pin for the ADC input, from the multimeter the value is very consistent.
Below is the values i get from the ADC. The multimeter shows a consistent 2.872V.
As you can see the lowest value read is 2329 and the highest read is 4045.
With the calculation the difference is
As I can see now, the values are changing very less. You will always see some variation depending on the resolution of ADC which is 12 bit in our case. When you calculate the value in Volts then you will see that the variation is really minimal.
Could you measure the voltage at the same moment with an external device, when you turn on the device and check if the values given by ADC are similar. For me this looks as a system problem, as in general the values are correct.